1. Field of the Invention
The present invention relates to a drive device for mirrors utilized in an optical system, such as an optical deflector for optical communications, an optical scanner, or a data recording and playback system for recording and/or playing back data relative to an optical recording medium, such as, for example, a magneto-optical disk drive, write-once-read-many (WORM) disk drive, phase-change disk drive, CD-ROM, DVD, or optical card.
2. Description of the Related Art
In an optical system, such as a data recording and playback system for recording and/or playing back an optical recording medium, such as CD-ROM, DVD, or optical card, a magneto-optical disk drive, WORM disk drive, phase-change disk drive, or an optical system, such as an optical scanner, a drive device for an optical element, such as a mirror, is utilized to skew a beam of light.
As an optical element support device, for example, a galvano-mirror 80 like that shown in FIG. 1 is disclosed in Japanese Unexamined Patent Application Publication No. 11-211969.
A hole is provided in the central part of a bottom wall portion 82 of a press-formed base member 81, the bottom surface of this bottom wall portion 82 is spherical, and is used as the mounting surface 83 for mounting and adjusting this galvano-mirror 80.
A spring assembly 84 is housed within this base member 81. This spring assembly 84 is constituted from a cantilevered fixed member 85, and a movable member 86, which is supported in a freely moving condition on the front surface side of this fixed member 85. This movable member 86 is supported by springs 87, 88 in a freely rotating condition around a mirror rotating axis R in parallel to axis Y as shown in FIG. 1.
A mirror 89 is mounted to the front surface of this movable member 86, a movable coil 90 is mounted so as to enclose the circumference of this mirror 89, and these movable member 86, mirror 89 and movable coil 90 constitute a movable portion.
Furthermore, the base member 81 of the front surface side of the mirror 89 is notched and open, and an open portion 91 through which light passes is formed.
A lead wire 92 is lead through from the upper and lower portions, respectively, of the above-mentioned movable coil 90.
Further, magnets 93 are arranged and affixed in the empty space portions on both sides of the spring assembly 84. Furthermore, each part in which each magnets 93 is housed forms a flat-shaped flat portion 94.
The above-mentioned springs 87, 88 have an S-shaped spring portion 95, which is shaped like the letter S, a not-shown reinforced conducting portion, which is formed by connecting to this S-shaped spring portion 95, and a terminal portion.
Thus, this galvano-mirror 80 is constituted such that the mirror 89 and movable coil 90 are affixed to the movable member 86, the opposite ends of the movable member 86 are linked to the fixed member 85 by means of two S-shaped springs 87 and 88, two magnets 93 are arranged in the base member 81 side facing two sides of the movable coil 90, the mirror 89 is supported in a rotatable condition around one axis, and the mirror 89 can be driven and rotated by applying current to the movable coil 90.
In a drive device for an optical element such as a mirror, there are cases when it is desirable to line up a plurality of optical element drive devices corresponding to a plurality of optical paths. When a plurality of galvano-mirrors 80, which are treated as the prior art optical element drive device shown in FIG. 1, are lined up, the pitch cannot be reduced. Another problem is that the number of parts increases.
Further, it is difficult to arrange systematically and compactly a plurality of the mirrors in the prior art shown in FIG. 1.